Peroxide removal using lead dioxide or manganese dioxide



United States Patent Office 3,306,846 Patented Feb. 2s, 1967 3 396 846runoxrnu REMOVAL rJsrNG LEAD moxruu R MANGANESE DIOXIDE Kailash C.Salooja, Wirral, England, assignor to Shell Oil substance inert toattack by the contents of the storage tank and have a surface to whichthe required dioxide will adhere. Suitable rods and plates have beenfabricated from, e.g., thermoplastic cast acrylic sheeting, which is 5resistant to aliphatic hydrocarbons, by softening the surg 9 acorporation of Delaware face with chloroform or carbon tetrachloride andsubse- 0 Drawing. Filed Dec. 29, 1964, Ser. No. 422,010 Claims priority,application Great Britain, Jan. 3, 1964, quenfly austmg the finfalyPowdered dloxlde on the Soft" 337/64 cned surface. Alternatively,treatment may be effected by 4 Claims C 20g 295) passing thehydrocarbons to be treated through a fixed 10 bed of catalyst or bysuspending in the storage tanks bags This invention relates to a processfor removing Organic which are inert to but permeable to gasoline andwhich peroxides from hydrocarbons. More particularly, the incontaincatalyst, e.g. nylon mesh containing the manvention concerns treatmentof gasoline-range hydrOCarganese or lead dioxide in a granulated orcoarsely powbons to increase their storage stability and resistance todered form. Replenishment of the dioxide or dioxides is deteriorationcaused by peroxide formation. easily achieved by simply replacing theused rods, plates On standing in storage in the presence of dissolved fags With new ones. A fixed-bed type of operation oxygen or an oxidizingatmosphere, certain hydrocarbons, may be conveniently carried out bysituating a bed of especially those containing unsaturates, tend to formpercatalyst in a refinery pipe line, thereby treating gasoline oxideswhich in turn promote gum formation and general for peroxide removal,for example, as gasoline is being instability. These peroxides probablypromote polymer- 2O pu ped fr m one tank to another. ization ofunsaturated hydrocarbons and may be polyrn- The process of the inventionis not limited to bulk quanerized themselves, The, presence of theseperoxides and tities Of gasoline such as are found in refineries, butcan resulting gum products is detrimental to the use and furbe also ppgarage gasoline storage tanks ev ther handling of the hydrocarbonproducts since they cause to gasoline tanks f a t m iles. The inventionis also clogging of screens and carburetor parts, valve sticking, usefulfor increasing the storage stability of pure hydrodiscoloration, andgradual deterioration of the product. carbons Which y he treated inSmall quantities, for

It has now been discovered that these peroxides can be p laboratory premoved from perQxide-containing hydrocarbons by con- The treatment Ofthe invention is generally carried Out tacting the hydrocarbons atambient conditions with lead at ambient Conditions With hydrocarbon inthe liquid dioxide, manganese dioxide or a mixture of lead and man-Phase The amounts of lead r m ganes dioxide ganese dioxides. Thesematerials are inexpensive solids used in the treatment are not eritiealbut generally range and provide economical and efficient removal ofperoxides, between about and 1 gram of catalyst P imperial therebyimparting excellent storage stability to the hydrogallon of gasoline tohe tTeated- Similarly the length-of b time of the treatment is notcritical and may vary from The process of th i enti i applicable t a idonly a few seconds, as in the case where gasoline is passed variety ofhydrocarbon. In general, however, the hydrothrough a fixed bed ofcatalyst, to Several y and even carbon fraction must not contain acidicsulfur or sulfur Weeks, as in the ease Where treatment is Carried outdiproducts but should contain at least a small amount of un- Teeny inthe Storage tank' The Process is operable Over a saturated material, forexample, at least about 0.1% un- Wide Variety of temperatures andPressures; ambient 0nsaturates. The presence of olefins is notessential, how- 40 ditiohs are generally satisfactory- The Catalyst y heever, since certain aromatics such as cumene and Tetraeither P leaddioxide P manganese id r a lin are believed to also contribute to gumformation. mixture of the two in any Proportions Inert terials Preferredfeeds for the process of the invention are hyor Promoters may also be pthe s al fact r is drocarbons in the gasoline range which areessentially free the Presence of at least one of the two i sfrom sulfurcompounds, such as hydrogen sulfide and To illustrate the effectivenessof the process of the inmercaptan, vention, certain hydrocarbons knownto be susceptible to Th t t t f th i ti may b ff t d b any peroxideformation during storage were treated with lead means so long assubstantially all of the gasoline to be nd/or manganese dioxide. Forcomparison, these hytreated is contacted with the particular dioxide ormixture drocarbons were also treated with known treating agents. ofdioxides being used. For example, a plurality of rods The amount ofsolid treating agents used in the tests was or plates which have beencoated with a film of lead and/ 0.5 gram per imperial gallon ofhydrocarbon. The tests or manganese dioxide may be suspended intogasoline were conducted for hours at ambient temperatures. storagetanks. Suitable rods or plates are made from a The results of the testsare found in Table I.

TABLE I Peroxide Content or Hydrocarbon Tested, Percent v01.

Treating Agent Used Hexene-l Hexene-2 4-Methyl Cyclohexene 1,4-1,4-Cyclo- Cumene pentene-2 Hexadiene hexadiene None 0. 085 6. 63 5. 402. 32 0. 59 0. 053 Topanol A (0.1%) 6. 25 1. 64 0. 047 Iron powder- Leadmonoxide. 0. 043 Lead dioxide 0. 018

Manganese dioxide Lead dioxide plus manganese dioxide 12,4-dimethyl-6-tertiary butyl phenol.

From these results it is apparent that catalysts of the invention areeffective for peroxide removal, whereas other known antioxidants andrelated materials are relatively ineffective.

Two gasolines were stored under oxidative conditions for one year andwere then tested for peroxide content immediately prior to and aftertreatment by the process of the invention. The first gasoline,designated as Gasoline I, was 100% catalytically cracked top gasoline.The second gasoline, designated as Gasoline II, was 100% full rangePlatform-ate gasoline. Each gasoline contained 150 p.p.m. of acommercial antioxidant, 2,4-dimethyl-6-tertiary butyl phenol.Catalytically cracked and Platformate gasolines were specifically chosensince they were considered to be the most important constituents ofpresent commercial gasolines. The results of the test are shown in TableII.

TAB LE II Peroxide Content of Hydrocar- Treating Agent Used (0.5 gramper bon Tested, percent vol.

Imperial gallon of hydrocarbon) Gasoline I Gasoline II 0.0067 0. 02000.0031 0.0107 Manganese diox 0.0021 0.0099 Lead/manganese dioxides (1:1weight ratio) 0. 0030 0. 0108 I claim as my invention:

1. A method of removing peroxides from a refined hydrocarbonsubstantially free from acidic sulfur-containing constituents whichcomprises contacting the hydrocarbon with a treating agent selected fromthe group consisting of lead dioxide, manganese dioxide, and mixturesthereof.

2. A method of removing peroxides from a refined gasoline substantiallyfree from hydrogen sulfide and mercaptans which comprises contacting thegasoline at ambient conditions with a treating agent selected from thegroup consisting of lead dioxide, manganese dioxide, and mixturesthereof.

3. The method of claim 2 wherein the treating agent is lead dioxide.

4. The method of claim 2 wherein the treating agent is manganesedioxide.

References Cited by the Examiner UNITED STATES PATENTS 2,057,629 10/1936 Morrell et al 208295 X 2,076,524 4/1937 Behrens 4450 2,115,7815/1938 Morrell 208-257 2,398,612 4/1946 Bergsteinsson et al. 2605972,809,921 10/1957 Vesely et a1. 208-257 X 2,970,104 1/1961 Snyder et al.208-295 DELBERT E. GANTZ, Primary Examiner.

R. H. SI-IUBERT, Assistant Examiner.

1. A METHOD OF REMOVING PEROXIDES FROM A REFINED HYDROCARBONSUBSTANTIALLY FREE FROM ACIDIC SULFUR-CONTAINING CONSTITUENTS WHICHCOMPRISES CONTACTING THE HYDROCARBON WITH A TREATING AGENT SELECTED FROMTHE GROUP CONSISTING OF LEAD DIOXIDE, MANGANESE DIOXIDE, AND MIXTURESTHEREOF.